Aquacultural Engineering最新文献

{"title":"Single pass saltwater disinfection using low voltage electrolysis: Potential implications for aquaculture systems","authors":"Jeffrey William Yuen ,&nbsp;Hei Yuet Sabrina Lam ,&nbsp;Avalon Berry ,&nbsp;Dawson Chalmers ,&nbsp;Ji Yang ,&nbsp;Ju Zhang ,&nbsp;Jason Chun-Ho Lam ,&nbsp;Celia Schunter ,&nbsp;Sophie St-Hilaire","doi":"10.1016/j.aquaeng.2024.102493","DOIUrl":"10.1016/j.aquaeng.2024.102493","url":null,"abstract":"<div><div>Open net pen saltwater aquaculture faces criticism due to the potential transmission of pathogens between fish farms and to wild stocks. To address this issue and improve the sustainability and growth of net pen farming, closed containment farms have been suggested, but the cost and feasibility of disinfecting large volumes of water in these types of farms is problematic. We explored the potential for using electrolysis to disinfect saltwater in a flow-through system with water flow velocities between 47 and 105 cm/s. This was the first step to investigating whether this technology could be applied to saltwater flow-through closed containment systems. Various voltage levels (3.3–9.0 V) were applied to generate chlorine from saltwater. We found the disinfection properties of the system varied with wattage (i.e., voltage × ampere), velocity of water flow over the electrodes, salinity of water, and residual chlorine contact time. Wattage was highly correlated with the production of chlorine, and this relationship was dependent on water flow (<em>p</em> = 0.0398). A slower flow velocity led to higher chlorine concentration, and the effect was more pronounced at higher wattages. Using a zero-inflated negative binomial regression model, we found the probability of full disinfection was increased by increasing wattage (<em>p</em> &lt; 0.001) and the residual chlorine contact time (<em>p</em> &lt; 0.001). The level of disinfection (count model) suggested the number of bacteria in the treated samples was determined by the interaction between wattage and flow (<em>p</em> = 0.0056) and the interaction between wattage and salinity (<em>p</em> &lt; 0.001). The bacterial count was also associated with residual chlorine contact time (<em>p</em> &lt; 0.001). The results of this study, although preliminary and limited in their scale, offering a potential solution for disinfecting large volumes of seawater, which could make closed containment fish farming in the ocean viable for reducing bacterial transmission within a farm and to wild fish stocks.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102493"},"PeriodicalIF":3.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel and sustainable valorization of biogenic waste into microbial protein based fish dietary ingredient in bioreactor: Process optimization and sustainable utilization","authors":"Thejaswini ,&nbsp;M.H. Chandrakant ,&nbsp;A.M. Babitha Rani","doi":"10.1016/j.aquaeng.2024.102483","DOIUrl":"10.1016/j.aquaeng.2024.102483","url":null,"abstract":"<div><div>Waste valorization is the concept of sustainability, and microbial floc is the valorised product of sustainable aquaculture. It converts nitrogenous waste into nutritious microbial protein that can replace fish meal partially or completely as feed for aquatic animals. The current study focuses on optimizing the process of production of microbial protein using aquaculture waste in a bioreactor and its utilization as feed for genetically improved farmed tilapia (GIFT) reared in inland saline groundwater with various inclusion levels. The retention time, aeration, and microbial flocculant (chitosan) were optimized to intensify the reaction, using a response surface methodology approach based on a full factorial experimental design. The chosen responses for evaluation were crude protein (CP), crude lipid (CL), and floc volume (FV). The interaction between aeration and retention time was found to play a significant role in the percentage of crude protein and crude lipid of microbial floc (p&lt;0.001). The floc volume was significantly influenced by retention time and chitosan concentration (p&lt;0.05). The process was optimized with 4 days of retention time, 30 ppm of chitosan concentration, and intermittent aeration (0.5 hr aeration and 0.5 hr no aeration), which resulted good quality microbial floc with a maximum CP of 24.74 %, a maximum CL of 2.13 %, and a FV of 13.75 ml. A completely randomized design with the inclusion of 0 %, 10 %, 20 %, and 30 % microbial floc (produced in a bioreactor) in feed was followed to evaluate the growth performance of GIFT. Among these, microbial flocs with a 20 % inclusion level showed a good growth trajectory. This study has shown that 20 % microbial floc meal in the diet is optimum for the growth of GIFT in inland saline groundwater. This study sustainably supports the waste valorization concept with microbial protein production in a bioreactor that is a suitable feed for GIFT.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102483"},"PeriodicalIF":3.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142703871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimizing alkalinity control in recirculating aquaculture systems (RAS): A dynamic modelling approach","authors":"Marie Aline Montjouridès ,&nbsp;Susanna Röblitz ,&nbsp;Håkon Dahle","doi":"10.1016/j.aquaeng.2024.102492","DOIUrl":"10.1016/j.aquaeng.2024.102492","url":null,"abstract":"<div><div>Maintaining good water quality is essential for successful fish production in land-based recirculating aquaculture systems (RAS). Numerous interdependent factors influence water quality parameters, making it difficult to evaluate which operational strategies are most favorable. Mathematical models and model simulations have proven to be powerful tools to evaluate how RAS design and operation are linked to RAS dynamics, but these models rarely implement pH and carbonate species as dynamic variables. Here, we present a dynamic model for RAS (dynRAS) that combines rates of TAN (total ammonia nitrogen) removal, fish growth, and <em>CO</em>₂ and TAN excretion, with a reaction model for pH and the carbonate system formulated based on the law of mass action. A novel aspect of our approach is the incorporation of a dosage system modelled by a Hill-function, enabling the exploration of diverse dosing strategies for pH and alkalinity management. The model was validated based on empirical data from a pilot scale RAS system operated with a feeding regime involving 12 h of feeding per day. We found that model simulations could be used to accurately predict diurnal cycling patterns in RAS water quality parameters. Furthermore, we made use of simulations to assess how diurnal cycling varies with changing pH and alkalinity levels. Model results emphasize the complexity of pH and alkalinity control in RAS in relation to overall water quality management. Based on our simulations, we argue that what should be considered as optimal pH and alkalinity in RAS depends on the state of the system. Accordingly, optimal pH and alkalinity thresholds may vary between different RAS units and between different time points of a rearing cycle. More generally, we demonstrate how modelling and model simulations can be an effective way of getting insights into the dynamics of complex RAS interactions and provide a valuable tool to efficiently explore effects of different operational strategies on water quality parameters.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102492"},"PeriodicalIF":3.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrodynamic responses of a large flexible net swinging in waves","authors":"Wude Xie ,&nbsp;Zhaoyang Jiang ,&nbsp;Lu Wang ,&nbsp;Zhenlin Liang","doi":"10.1016/j.aquaeng.2024.102491","DOIUrl":"10.1016/j.aquaeng.2024.102491","url":null,"abstract":"<div><div>In deep-sea aquaculture cages, large flexible nets are usually mounted on the steel frames of aquaculture cages, which are easily broken. When a cage vibrates over time, the flexible nets also oscillate, causing relative motions with respect to fluid flows. This study focuses on the hydrodynamic behaviors of a large flexible net swinging in waves, in which three different types of swings are simulated with the swing center located above, on, and below the net, respectively. The incoming waves are simulated using the Airy wave theory. The nonlinear vibrations of the flexible net in three dimensions are solved using the lumped-mass method. The influences of swing amplitudes and frequencies on the vibrations of the net are analyzed in detail. It can be known that with the increase of swing amplitude, the vibration displacements of the net in the horizontal direction decrease, while they increase in the vertical direction. Furthermore, the dynamic tensions of net twines increase as the swing angular frequency rises.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102491"},"PeriodicalIF":3.6,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unsteady flow dynamic response in the cylinder-netting structure for the design of offshore fish farm systems using an SST-IDDES turbulence model","authors":"Bruno Thierry Nyatchouba Nsangue ,&nbsp;Hao Tang","doi":"10.1016/j.aquaeng.2024.102480","DOIUrl":"10.1016/j.aquaeng.2024.102480","url":null,"abstract":"<div><div>An improved comprehension of the flow dynamics and hydrodynamic features of the interaction between the cylinder and nettings, crucial elements of offshore aquaculture systems, can optimize the development of environmentally friendly and sustainable large-scale aquaculture pens. This study investigates the instantaneous flow fields and hydrodynamic response in the interaction between the cylinder and netting structures using a high-fidelity Computational Fluid Dynamics approach based on the k-ω shear stress transport-improved delayed detached eddy simulation turbulence model within the Large Eddy Simulation region. The Richardson Extrapolation method was employed to assess the convergence of the numerical solutions across various levels of mesh refinement. The conducted research revealed that the inclusion of the cylinder resulted in an increase in the drag coefficient ranging from 2.25 % to 36.78 % due to the complex interaction between the combined netting-cylinder, shear layer instabilities, and vortex shedding, when compared to the two individual nettings. As Reynolds number and cylinder diameter increased, cylinder drag coefficients decreased, causing large-scale vortex shedding and unsteady turbulent wake flow. Furthermore, the wake interactions of the netting are relatively strong with low flow velocity when the solidity ratio and twine diameter increased due to the disruption caused by the netting-twine, mesh shape, and netting position in the flow passage. The drag and lift coefficients of the combined cylinder-netting structure increased with increasing solidity ratio, inclination angle, and decreasing flow velocity. The Fourier analysis showed that the hydrodynamic coefficients of only the cylinder and single netting are primarily low-Strouhal numbers activities, while the hydrodynamic forces of the combined cylinder-netting structure are primarily low-frequency activities connected to unsteady turbulent flow streets. The understanding of the hydrodynamic and flow instabilities that occur close to the wake of the contact between the cylinder and the nettings is of utmost significance for the purpose of optimizing the design of offshore aquacultural structures, particularly for situations that are characterized by biofouling.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102480"},"PeriodicalIF":3.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142551920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A probabilistic framework for offshore aquaculture suitability assessment using bivariate copulas","authors":"R. Santjer ,&nbsp;P. Mares-Nasarre ,&nbsp;L. Vilmin ,&nbsp;G.Y.H. El Serafy ,&nbsp;O. Morales-Nápoles","doi":"10.1016/j.aquaeng.2024.102479","DOIUrl":"10.1016/j.aquaeng.2024.102479","url":null,"abstract":"<div><div>Aquaculture at sea is gaining increasing importance, not only as a (local) food source but also due to its potential of being combined with other offshore activities such as wind parks. Nevertheless, experience of offshore aquaculture is limited. This study aims to provide a framework to evaluate offshore aquaculture suitability accounting for the probabilistic dependence between relevant variables. This framework is applied to obtain suitability maps of aquaculture for the North Sea for the blue mussel <em>Mytilus edulis</em> and the sugar kelp <em>Saccharina latissima</em>. For each of these species, three ecological variables are selected and the optimal growth and critical survival limits are defined. Here, suitability is defined as the probability of meeting these conditions. Data on the selected variables is extracted from a large-scale 3D hydrodynamic and ecological model of the northwest European Shelf, of which daily extremes are sampled. The probabilistic model is developed using bivariate copula models, which are fitted to each variable pair to describe their joint distribution function at each studied location. Empirical distribution functions are used to describe the univariate distribution function of each variable and location. Using Monte-Carlo simulations, the probability of meeting the optimal and critical limits is estimated and suitability maps accounting for the probabilistic dependence between the variables are generated. In addition, suitability maps disregarding the dependence are generated and compared to those accounting for the probabilistic dependence. It was found that considering the dependence between variables significantly improves the accuracy of the results for optimal and critical growth conditions for both species. The presented method allows to identify potential areas where blue mussel and sugar kelp cultivation is the most suitable. For instance, in this study, a north-south elongated area west of the German and Danish coast appears to be most suitable for blue mussels, while estuaries and rivers are found the most suitable for the sugar kelp.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102479"},"PeriodicalIF":3.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aquaculture fish counting and mass estimation method via vibration signal processing","authors":"Liwen Qian ,&nbsp;Guoyan Yu ,&nbsp;Haochun Liu ,&nbsp;Junxi He ,&nbsp;Zijian He","doi":"10.1016/j.aquaeng.2024.102478","DOIUrl":"10.1016/j.aquaeng.2024.102478","url":null,"abstract":"<div><div>Information on the mass and counts of fish at different growth stages is crucial for precision feeding management and the improvement of fish farming environments. Grading operation plays a significant role in management and harvesting of cage culture. In this study, a counting and mass estimation of fish via vibration signal process method was proposed, using a roller-type fish grader to count and estimate the mass of fish during the grading process. First, we replicate fish dropping events during the grading process, when fish impact the mass measurement plate, on a test bench, and waveform data from vibration sensors located on the mass measurement plate were collected. Secondly, the waveform signal was analyzed, and trigger thresholds were set. When the signal exceeded the threshold, performed mathematical operations on the signal's data for counting and mass estimation until the signal left the threshold. The method was conducted on a test bench, and the results showed a coefficient of determination (R²) of 0.9970 and a Root Mean Square Error (RMSE) of 4.1724 g for mass estimation. Furthermore, the method was validated on a roller-type fish grader in practical applications, achieving average R² of 0.9862 and RMSE of 8.8529 g. The accuracy of fish counting reached 100 %. These experimental results demonstrate the proposed method can accurately count and estimate mass of fish.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102478"},"PeriodicalIF":3.6,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on hydrodynamic performance of the semi-submersible vessel-shaped fish cage","authors":"Guoqiang Li ,&nbsp;Xiaobin Li ,&nbsp;Yonghe Xie ,&nbsp;Chunhui Zhao ,&nbsp;Peng Xu","doi":"10.1016/j.aquaeng.2024.102482","DOIUrl":"10.1016/j.aquaeng.2024.102482","url":null,"abstract":"<div><div>Deep-sea net cages play a vital role in expanding offshore farming in modern marine fisheries. In this paper, a model-scale 1:40 tank experiment was conducted for a vessel-shaped truss-structured single-point mooring deep-sea aquaculture net cage. The study focused on the hydrodynamic characteristics, including the effect of current, wave, and net on the mooring force, heave, and pitch motion behaviors. Experimental results indicate that the mooring force increases with the current velocity, draught of the cage, and wave height, but decreases with the wave period increase. Both heave and pitch movements amplitudes increase with wave height. While heave motion amplitude initially declines and then ascends with wave periods, pitch motion shows the opposite pattern. Besides the net has an obvious damping effect on the pitch motion. These results can provide data support for the design and offshore installation of vessel-shaped truss-structured net cages in the future.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102482"},"PeriodicalIF":3.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A robotic fish processing line enhanced by machine learning","authors":"Sangam Mainali,&nbsp;Cheryl Li","doi":"10.1016/j.aquaeng.2024.102481","DOIUrl":"10.1016/j.aquaeng.2024.102481","url":null,"abstract":"<div><div>This paper presents the design of a comprehensive automatic fish processing line utilizing machine learning algorithms. The processing line encompasses several essential steps, including fish identification by type, fish sorting by size, fish orientation based on shape, and fish cutting at the optimal chopping points. The primary objective of this design is not just automation but also maximizing economic benefits by preserving the maximum amount of fish meat during the cutting process, achieved through the application of machine learning algorithms. To accomplish these goals, we employ a combination of transfer learning and convolutional neural networks to establish criteria for actions across all stages of automatic fish processing. At the heart of the processing station is a conveyor belt equipped with numerous sensors and lenses. Positioned along this conveyor belt are two robotic arms, responsible for precise positioning and cutting operations, all guided by the machine learning algorithms. To provide a visual representation of these design concepts, we have created a 3D SolidWorks model.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"108 ","pages":"Article 102481"},"PeriodicalIF":3.6,"publicationDate":"2024-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal dynamics of protist communities and environmental factors in the horizontal flow-polyculture pond aquaculture model of Sinonovacula constricta","authors":"Minhai Liu ,&nbsp;Zhongneng Yan ,&nbsp;Chengwei Huang ,&nbsp;Zhihua Lin ,&nbsp;Zhilan Peng ,&nbsp;Chenxi Zhao ,&nbsp;Xiafei Zheng","doi":"10.1016/j.aquaeng.2024.102477","DOIUrl":"10.1016/j.aquaeng.2024.102477","url":null,"abstract":"<div><div>The horizontal flow (HF)–polyculture pond (PP) model has emerged as a new aquaculture model that has attracted considerable attention. The growth of <em>Sinonovacula constricta</em> in the HF is highly dependent on phytoplankton in the PP; however, the current understanding of the basic microbes in the HF-PP model research remains insufficient. To address this knowledge gap, we analyzed the temporal dynamics of protist communities in water and sediment samples obtained from the HF and PP in this study. In addition, we measured the temporal variations in physicochemical factors in these water and sediment samples. A comparison of water quality data between HF and PP revealed that HF effectively reduced the total nitrogen (TN) and total phosphorus (TP) levels in the polyculture ponds. Furthermore, Diatomea and Ciliophora were the predominant phyla in all samples. In the horizontal-flow water samples, significant alterations were observed over time in <em>Skeletonema</em>, <em>Strombidium</em>, and <em>Gyrodinium</em> genera. The dynamic pattern of the genus in the polyculture pond water (PPW) was similar to that in the horizontal flow water (HFW). Furthermore, <em>Skeletonema</em> abundance decreased over time in the horizontal flow sediment (HFS). <em>Skeletonema</em> and <em>Cyclotella</em> were dominant in polyculture pond sediment (PPS). There was a certain degree of community succession throughout the experiment in the HFW and PPW, but not in the HFS or PPS. Correlation analysis revealed that water temperature (WT), salinity(SAL)，dissolved oxygen (DO), pH, phosphate, and silicate played key roles in driving variations in the protist community. These findings contribute to our understanding of complex protist community dynamics within the HF-PP aquaculture model, shedding light on the roles of various environmental factors in shaping protist communities and water quality.</div></div>","PeriodicalId":8120,"journal":{"name":"Aquacultural Engineering","volume":"107 ","pages":"Article 102477"},"PeriodicalIF":3.6,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528376","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}